OPA4277-EP

SBOS714 – NOVEMBER 2014

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9 Power Supply Recommendations

OPA4277 operates from ±2- to ±18-V supplies with excellent performance. Unlike most operational amplifiers

which are specified at only one supply voltage, the OPA4277 is specified for real-world applications; a single limit

assured performance as a customer using ±15-V supplies. In addition, key parameters are assured over the

specified temperature range, –55°C to 125°C. Most behavior remains unchanged through the full operating

voltage range (±2 to ±18 V). Parameters which vary significantly with operating voltage or temperature are shown

in the typical performance curves.

10 Layout

10.1 Layout Guidelines

The leadframe die pad should be soldered to a thermal pad on the PCB. Mechanical drawings located in

Mechanical, Packaging, and Orderable Information show the physical dimensions for the package and pad.

Soldering the exposed pad significantly improves board-level reliability during temperature cycling, key push,

package shear, and similar board-level tests. Even with applications that have low-power dissipation, the

exposed pad must be soldered to the PCB to provide structural integrity and long-term reliability.

The OPA4277 has very-low offset voltage and drift. To achieve highest performance, optimize circuit layout and

mechanical conditions. Offset voltage and drift can be degraded by small thermoelectric potentials at the

operational amplifier inputs. Connections of dissimilar metals generate thermal potential, which can degrade the

ultimate performance of the OPA4277. Cancel these thermal potentials by assuring that they are equal in both

input terminals.

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Keep the thermal mass of the connections made to the two input terminals similar.

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Locate heat sources as far as possible from the critical input circuitry.

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Shield operational amplifier and input circuitry from air currents such as cooling fans.

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